B&W HTM4s verses HTM2 center speaker

What's the difference? Are there any significant sonic differences? The price difference is approximately $400-$600 which IS significant. This question was asked by another A'goner a while back and no one responded. I have the same question and would appreciate a response from someone who has heard any differences.
The bigger question is what are your current Front L/R speakers. In other words what timbre match are you trying to achieve. The FST driver has been re designed for the HTM4s. If I am not mistaken the tweeter is mounted on top of the cabinet instead of in a shallow ontop of the cabinet.
My fronts are B&W 802N. I do not have room for the bigger HTM1 or HTM3s.
I think that big difference between old and new series is because, new series (HTM1D-HTM2D-HTM3S and HTM4S) have loudspeakers redesigned.
New series use a simple crossover (6dB/oct) because loudspeakers byself limited the frequency response.
Old models have need a more complex cross-over filter to obtain the same output curve.
With less cross over components the sound might be more clear

The HTM4S is a "better" speaker. If you plan on upgrading any time soon to 80xS type Fronts, then I would get the HTM4S.

The HTM2 is the match for your N802 speakers. If you plan on keeping the N802 speakers for a while, then that is the one you want.

Those are perfect world recommendations. I started with the HMT1 in front, which is the same match as the HTM2. Later I added 804S and 803S speakers. Now I have a mismatch up front. You can hear a slight mismatch, but it isn't bad. It is still a sweet sounding setup.

To correct it, I would have to spend ~$800 to upgrade it. So far I have found other parts of my audio system that need more attention/fixing than this mismatch so I am fixing them first.

If you don't have a Center or plan to upgrade to 80xS speakers anytime soon, I would go ahead with the HTM4S. If you already have the HTM2, I would keep it and address other parts of your system 1st.

The B&W speakers need ALL the help they can get dyanmically. And simplifying the crossover is a big help here. Any inmprovement in this departement is very very welcome and needed!